This invention relates generally to magnifying lenses, and more particularly to magnifying lenses suspended from the user's neck.
Prior art magnifying lenses adapted for hanging from the user's neck are well represented by U.S. Pat. Nos. 2,122,753 and 3,753,610. Such lenses are generally used under a reading lamp placed above the chair in which the user is sitting while performing needlepoint, darning, knitting, crocheting, and similar handicraft work as well as reading or any other close work functions which may require magnification of the workpiece, such as, for example, precision assembly, machining or grinding operations.
Under these prior art overhead lighting arrangements, users of neck supported magnifying lenses encounter a number of light-related problems. For example, overhead lighting is often just not bright enough in the workspace under the lens. This usually results in either moving the light closer to the user or the user moving closer to the light or in eyestrain. The use of more intense or focused overhead light sources does not always solve the problem because bright lights tend to produce glaring reflections of the light itself in the lens. This is annoying and even harmful to the user's vision. Furthermore, even if the user does obtain the proper workpiece and magnifying lens orientation to an adequate overhead lighting source, there are usually occasions when the user's head must be bent closer to the lens for better observation of particularly close work. Aside from being very tiring on the neck muscles, this downward bending of the head usually blocks out a portion of the overhead light and creates a distracting shadow over the workspace. Even if particularly close work is not required, the user is constantly required to find and laboriously hold the body position where the workpiece, the lens and the overhead light are in a precise relationship. Change, however, is inevitable. The progress of the work itself produces change; the user must reach for another tool, or perform some auxiliary work function; or perhaps the work must be taken to an entirely new workstation. Each such change requires a new orientation to the light and thus contributes to user eyestrain and fatigue.
Lighted, hand-held magnifying lenses of the type taught in U.S. Pat. No. 2,384,528 have not solved the handicraft worker's lighting problems because use of one hand is lost in holding such lenses. Furthermore, this type lens does not provide sufficient, uniform vertical depth of light in the workspace. This is because their light and their lens are in substantially the same horizontal plane. Therefore, their light is not delivered substantially perpendicular to the vertical optical field of the lens to provide the desired uniformly lit depth in the workspace, but rather their light is delivered at some lesser angle. This lesser angle can create problems in that as the angle between the vertical optical field, the workpiece and the light source decreases, the greater becomes the likelihood that light reflected from the workpiece will shine directly back into the user's eyes. This type of lighted lens also lacks the capability of varying the angle between the lens and the light source, i.e., the light and the lens remain in the same plane as the lens is tilted toward or away from the workpiece. The end result of these conditions is that use of these hand-held, lighted lenses is generally restricted to two dimensional horizontal work such as reading, rather than use in a three dimensional workspace where both hands must be employed in order to work on a workpiece requiring three dimensional work operations.
Therefore, the primary object of this invention is to provide an adequate, uniform, low reflection generating light to the workspace under a neck supported magnifying lens regardless of the user's head position, and thereby reducing the fatigue normally associated with close work. Another object is to provide the user with the capability of carrying the workpiece with both hands to a new work station while holding the light in the workspace nearly constant in the new workpiece location.